This invention relates to a chemical laser and, more specifically, to a chemcial laser pump adapted to quickly remove exhaust gases from the laser cavity.
Chemical lasers typically involve a reaction with hydrogen and/or deuterium and fluorine, chlorine, bromine or iodine in diluent gases of N.sub.2, He, etc., to produce hydrogen and deuterium halides. The laser action takes place at pressures of about 15 torr and below from halides such as HF* and/or DF* molecules in the excited vibrational states. Decay to ground level of these excited HF and DF molecules produces a lasing action with an output spectrum varying from about 3.6-4.0 microns for DF and 2.6-2.9 microns for HF.
Not only must population inversion requirements be met, but high temperature and low pressure requirements must also be maintained for lasing action to be sustained. Additionally, exhaust gases at ground level state must be removed very quickly from the laser cavity otherwise they will quench the lasing action. These exhaust gases are at temperature as high as 3000.degree. K.
Hence, the usual practice is to pump the exhaust gases along with the carrier gases such as nitrogen or helium from the laser cavity into the atmosphere. It will be appreciated that at low altitudes it is impossible to naturally vent these low pressure gases into the atmosphere. Pumping requirements are attained using large capacity mechanical ejector, or turbo mechanical pumps; however, this mode of operation presents several difficulties. To begin with, venting hydrogen and deuterium halides to the atmosphere causes a pollution problem. Also, the large weight of the pump can preclude employment of a chemical laser in an aircraft where weight is important.
It is, therefore, an object of this invention to provide a chemical laser provided with a pump suitable for removing high energy, low pressure exhaust gases from the laser cavity without the necessity of discharging these gases into the surrounding atmosphere.
Another object is to provide a process for removing exhaust gases from the laser cavity of a chemical laser.
Another object is to provide a pump for a chemical laser which is smaller and ligher than conventional large capacity mechanical pumps.
Another object is to provide a pump for a chemical laser, the pump having no moving parts and which provides complete containment of the exhaust gases from the laser cavity.